Reading the comments so far, for me they reinforce the point - it's not that HR "is on the side of the company" that's the point, it's that if they are that way, then your culture supports them being that way. If Uber HR blows off complaints, the root issue isn't that HR blows off complaints, it's that the company culture encourages and supports them doing so. If HR is a "policing role", then something in the culture supports them being the police.

If these are not the outcomes you want, change the culture. We choose, create, and/or attract the reality in which we operate - so what are we doing to bring this into being?